1. Technical Field
The disclosure relates to a multi element trailer jack capable of being configured for and enabling rapid gross and incremental adjustments in the height of a trailer.
2. Background
Many trailers have jacks that enable individuals operating the trailer to hitch and unhitch the trailer from the towing vehicle. Typically, such trailers are used for boats, campers and other similar towed vehicles. The trailer jacks are customarily rigidly fixed to the trailer, often by welded or bolted connections and have used a threaded mechanism advanced by a crank to achieve the adjustments in height needed for operation of the trailer. In attaching the trailer to the towing vehicle, elements of the jack must first be extended to the ground, the tongue of the trailer then raised above the hitch mechanism on the towing vehicle through application of a cranking or rotational movement to the threaded mechanism that operationally raises the trailer tongue and, once situated over the hitch mechanism of the towing vehicle, the tongue of the trailer is lowered into place so that the trailer may be coupled to the hitch mechanism of the towing vehicle by reversing the same rotational or cranking application to the threaded mechanism. To unhitch the trailer, the reverse steps are needed. In preparation for actual transport, the element of the jack extending from the trailer to the ground must be substantially retracted to provide adequate clearance between the roadway and the lower portion of the jack during travel. See U.S. Pat. No. 4,842,252 which is incorporated herein by reference for further discussion, the disadvantages of the threaded mechanisms for rapid adjustments in height and the effort needed by an operator to make the height adjustments necessary to couple and uncouple a towing vehicle and a trailer with a threaded mechanism alone.